diff --git a/src/objective-c/GRPCClient/GRPCCall.h b/src/objective-c/GRPCClient/GRPCCall.h
index 178a446c8b406b783aaf416ad826bcd329da2771..4d90cfd3847924146d6f4053c6eab8994e3b3bf4 100644
--- a/src/objective-c/GRPCClient/GRPCCall.h
+++ b/src/objective-c/GRPCClient/GRPCCall.h
@@ -167,7 +167,7 @@ extern id const kGRPCTrailersKey;
  * The authority for the RPC. If nil, the default authority will be used. This property must be nil
  * when Cronet transport is enabled.
  */
-@property (atomic, readwrite) NSString *serverName;
+@property (atomic, copy, readwrite) NSString *serverName;
 
 /**
  * The container of the request headers of an RPC conforms to this protocol, which is a subset of